Who is Maxwell from Wieland; and Memoirs of Carwin the Biloquist and what is their importance?

Maxwell seduced Major Stuart's wife in order to attain revenge on the man. As a result, Mrs. Stuart fled to America, taking her daughter, Louisa, with her. When Stuart learned the truth about the affair, he confronted Maxwell and challenged him to a duel. Stuart, however, was murdered before the duel could take place.